A "tipping point" and the 4% rule?

The 4% rule gets flogged so often, the poor thing.  It more or less worked for Bengen due to its getting "close enough" over a "hard coded 30 years" using historical data that happened to be pretty good but which may never replicate. Or maybe it will.   My last illustration of withdrawal rates vs portfolio longevity has an implied comment on the 4% rule: "it's just one thing among an infinity of things." There is zero guarantee that it'll work.  On the other hand, it looks to me that, even though that comment is true, the 4% spend level seems to be a gateway to what I'll call a tipping point.

By tipping point I mean that a 4% spend, given a balanced portfolio allocation with its associated realized geometric return expectations for the future, seems to be about where portfolio longevity "tips" from more finite space (PL in years is < infinity) to more infinite space (PL lasts forever).  See here below in a revision of the chart I used in the last post. Assume that 4% return and 12% vol is more or less near where Bengen's 50% US equity 50% 5 year Treasury would land, which I think might be true. Then somewhere between a 4% and 3% spend (let's assume 2% withdrawal on the other side is, or can be, effectively a perpetual process) portfolio longevity "tips" from finite world to infinite.  Take a look and tell me what you think...

also, just for the hell of it, I amped up the iterations 10x to 500k to see how it fills out. There was no reason for this except curiosity...